Animal studies suggest that the vestibular system autoregulates its sensitivity in response to prolonged low- or high-intensity motion in order to maintain an optimal working range. In humans, corresponding attenuations of vestibular responses after prolonged high-intensity motion exposure have been demonstrated. Here we explored whether a complementary increase in human vestibular sensitivity can be induced by motion conditioning at low-intensity, subliminal amplitudes. In 9 healthy subjects, vestibular perceptual thresholds for translational motion along the inter-aural (IA) axis were determined in a direction-recognition task at baseline as well as immediately and 20-min after subliminal motion stimulation. The subliminal conditioning stimulus consisted of a 20-min 1 Hz sinusoidal IA translation at an amplitude of 70% of each subject’s baseline IA threshold (2.09 ± 0.78 cm/s² peak acceleration). In a second set of experiments, we tested whether IA conditioning also influences perceptual thresholds for yaw rotations. Immediately after conditioning, IA thresholds were effectively lowered (p = 0.002; mean reduction: 28.8 ± 4.5%). These improvements were transient and thresholds had returned to baseline level 20 min after conditioning (p = 0.015). Vestibular sensitivity for yaw rotations remained on average unaltered after IA conditioning indicating that sensitizing effects might be selective for the end-organ-specific vestibular pathways being stimulated during conditioning. These findings demonstrate that human vestibular sensitivity can be enhanced by subliminal sensory conditioning, similar to sensitizing effects observed in other sensory modalities. Conditioning-induced sensitization of vestibular responses may be an effective treatment for decrements in vestibular sensitivity in the elderly and patients with vestibular hypofunction.

动物研究表明，前庭系统可响应长时间的低强度或高强度运动而自动调节其敏感性，以维持最佳的工作范围。在人类中，长时间的高强度运动暴露后，前庭反应相应减弱。在这里，我们探讨了在低强度，阈下振幅下的运动调节是否可以引起人前庭敏感性的互补增加。在9名健康受试者中，在基线以及下潜意识运动刺激后立即和20分钟后的方向识别任务中确定了沿耳间（IA）轴平移运动的前庭感知阈值。²峰值加速度）。在第二组实验中，我们测试了IA条件是否还会影响偏航旋转的感知阈值。调理后，IA阈值立即有效降低（p  = 0.002；平均降低：28.8±4.5％）。这些改善是短暂的，调节后20分钟阈值已恢复到基线水平（p = 0.015）。IA调节后，前庭对偏航旋转的敏感性平均保持不变，这表明在调节过程中刺激的终末器官特异性前庭通路可能具有选择性的增敏作用。这些发现表明，通过前庭下的感觉调节可以增强人的前庭敏感性，类似于在其他感觉方式中观察到的致敏作用。条件诱发的前庭反应敏化可能是降低老年人和前庭功能低下患者前庭敏感性降低的有效方法。